computeStackDepth(self)

Approach is to compute the stack effect of each basic block. Then find
the path through the code with the largest total effect.

_lookupName(self,
name,
list)

Return index of name in list, appending if necessary

This routine uses a list instead of a dictionary, because a dictionary
can't store two different keys if the keys have the same value but
different types, e.g. 2 and 2L. The compiler must treat these two
separately, so it does an explicit type comparison before comparing the
values.

getConsts(self)

Return a tuple for the const slot of the code object

Must convert references to code (MAKE_FUNCTION) to code objects
recursively.